"There was a research proposal which they [the formulating team at Bayer] undertook, there was no expectation of
success and they found to their surprise that they had a formulation which was rapidly dissolving on a poorly soluble
acid labile compound good bioavailability in vivo against all experience, against all of the scientific knowledge that
they had and we still cannot understand how it works. . . ."
[23] Dr Rue disagreed. In his view the fact that a rapidly dissolving micronised form of DSP, known to be acid labile,
would not in fact degrade in vivo would have been experimentally determined by the skilled formulator
through in vivo tests performed as a matter of routine at an early stage of the development. The three arm
test eventually conducted by Bayer, so he testified, should have been done as a matter of routine at an
earlier stage. Had this been done, the "problem" contemplated by Bayer in the light of the in vitro results,
would routinely have been established to be no real problem at all. His answer to Prof Davies' view that the
invention, protected by the patent in suit served to resolve a particular problem was therefore in short that
the skilled formulator would have known at an early stage that the perceived problem was not a real problem
at all.
Infringement
[24] Against this background I can now turn to the question: does Pharma's Ruby product constitute an
infringement of claim 1 of the 2004 patent? In Letraset Ltd v Helios Ltd 1972 (3) SA 245 (A) at 274GH [also
reported at [1972] 3 All SA 191 (A) Ed], the approach to this question was formulated as follows:
"The determination of the question as to whether or not plaintiff has proved an infringement of his patent turns upon a
comparison between the article . . . involved in the alleged infringement and the words of the claims in the patent. If
the article or process falls within the ambit of the claims, properly construed; an infringement is proved. But the
article or process will not be regarded as falling outside the scope of the claims if such differences as the comparison
may disclose are not matters of any substance. In making the comparison the law looks at the essence of what is
contained in the claim and will not allow what is described as the 'pith and marrow' of the protected invention to be
pirated. The evaluation of what is the substance or essence of an invention is a matter for the 'good sense' of the
judicial tribunal seized with the enquiry."
Page 311 of [2014] 4 All SA 302 (SCA)
[25] Claim 1 of the 2004 patent is formulated as follows:
"A pharmaceutical composition comprising:
as a first active agent drospirenone in an amount corresponding to a daily dosage, on administration of the
composition, of from about 2 mg to 4 mg, and
as a second active agent ethinylestradiol in an amount corresponding to a daily dosage of from about 0.01mg to 0.05
mg,
together with one or more pharmaceutically acceptable carriers or excipients,
wherein at least 70% of said drospirenone is dissolved from said composition within 30 minutes, as determined by
USP XXIII Paddle Method II using water at 37ºC as the dissolution media and 50 rpm as the stirring rate."
[26] It is common cause between the parties that this claim can be divided up into the following five features or
integers:
A.
A pharmaceutical composition comprising:
B.
as a first active agent drospirenone in an amount corresponding to a daily dosage, on administration of
the composition, of from about 2mg to 4mg;
C.
as a second active agent ethinylestradiol in an amount corresponding to a daily dosage of from about
0.01mg to 0.05mg;
D.
together with one or more pharmaceutically acceptable carriers or excipients; and
E.
wherein at least 70% of said drospirenone is dissolved from said composition within 30 minutes, as
determined by USP XXIII Paddle Method II using water at 37ºC as the dissolution media and 50 rpm as
the stirring rate.
[27] It was not in dispute that Pharma's product includes integers AD of the claim. The debate, therefore, turned
on integer E. In broad outline the debate went along the following lines: according to the interpretation
contended for by Bayer, the claim includes within its scope, DSP having the rapid dissolution rate specified in
accordance with a known method of determination without an enteric coat, no matter how that dissolution
rate had been achieved. By contrast, the interpretation relied upon by Pharma is that the claim is limited to
the achievement of the specified rapid dissolution by way of micronisation on DSP (or of the possible
alternative method of dissolving DSP in a suitable solvent and spraying the solution onto the surface of an
inert carrier).
[28] In this regard it is common cause that the DSP used in the manufacture of Pharma's Ruby product attains the
dissolution rate specified in integer E, but that it is not provided in micronised form or dissolved in a solvent
and then sprayed onto the surface of inert carrier particles. Instead a solution containing the DSP is added as
a bulk liquid which is distributed uniformly throughout the granules used in the formulation by means of a high
speed mixer or granulator. Hence it is clear that if the interpretation contended for by Bayer is accepted, Ruby
falls within the compass of integer E and hence of the claim but not if Pharma's interpretation of the claim is
sustained.
[29] Bayer's case is that claim 1 protects the invention described by Prof Davies. The contrary position taken by Dr
Rue and Pharma is that if there was indeed an invention as described by Prof Davies which they